angular momentum?

Question

how does angular momentum affects a ball rolling down a slope? and how do i overcome it if i still must use a ball to conduct an experiment but i dont want the angular momentum to affect the final reading? thanks

can anyone tell me how does it affects a ball rolling down a slope?

how to minimize the error in the experiment in a mathematically way?

Answer 1

Get a perfect sphere to be your ball. Then lubricate the ball and the slope so that the ball does not rotate.

Answer 2

Come on! You really should spend a little more effort posing your question well. How old are you, 12?

I will attempt to divine your true intent.

A ball rolling down a slope will not accelerate as fast as the same ball sliding down an (icy) slope because only part of the energy from the earth's gravitational pull is converted into translational motion (linear momentum). The rest is converted into rotational motion (angular momentum).

If the ball slides down the slope without rotating, all the potential energy initially stored in the earth's gravitational field will be converted into translational motion and the ball will be moving faster.

If you don't want angular momentum to play a role in your experiment, arrange it so the ball slips or slides down the slope because the slope is slippery, or the ball is slick, or the ball rides on a cart of negligible mass and with very small and lightweight wheels, or on an air cushion, or is magically levitated using the dark side of the force, or some other such thing.

Answer 3

The spinning ball is a spinning body, just like a bicycle tire or a top. The angular momentum exerts a moment force along the axis of the ball (pretend that there is a stick in the ball and it rolls so the stick is pointing straight out the axis of the ball roll). In such a case, the rolling ball exerts a slight force on the ramp as it travels. The force may cause some friction and slow the ball. Perhaps a lubricant or teflon track would minimize the friction.

The moment may also affect the trajectory of the ball if it is spinning fast off the track. That would mean it veers off the centerline of the track. Just measure the deviation from the centerline and adjust the landing point back to the centerline...but I doubt if it is much.

Answer 4

In addition to linear momentum due to the motion of the center of gravity, a rolling ball has angular momentum equal to Iw, where I is the moment of inertia and w is the angular velocity. However, for calculations involving a ball rolling down a slope, it's usually angular kinetic energy that you need, which is 0.5*I*w^2. The potential energy, linear kinetic energy, and angular kinetic energy need to have a constant sum. If you don't want angular momentum to affect your experiment, I guess that means you want angular momentum to be zero. The only way to do that is to make sure that the ball purely slides across the surface. Rolling is caused by friction, so you need to eliminate friction between the ball and the surface of the slope. Friction can't be truly eliminated, or even made negligible in an amateur lab, but you just need to get it as low as you can.

Answer 5

Since you want to roll the ball in your experiment there is no way to get rid of angular momentum.

That is like saying:" I want to conduct an experiment with a moving ball but I do not want the ball gets linear momentum".

Suggestion:
Modify the result of your experiment by deducing the effect of angular momentum in your calculations.

Answer 6

angular momentum exists only on a circular path. a body moving down a slope has only linear momentum